Improvement in treadles for sewimg-machiwes



A. B. SHAW." Treadl es for Sewing-Mhchines. Bil-13.4 820. Patented Jan. 14, 1873.

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AI B. SHAW, OF MEDFORD, MASSACHUSETTS. v

IMPROVEMENT IN TREADLES FGR SEWlNG-MACi-HNES.

Specification forming part of Letters Patent No. 134,820, dated January 14, 1872 To all whom it may concern:

Be it known that I, AI B. SHAW, of Medford, in the county of Middlesex and State of Massachusetts, have invented an Improved Method of Applying Treadle Attachments to Sewing-Machine Driving or Balance Wheels, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing making part of this specification, in which- V Figure l is a perspective view of a sewingmachine table with my improved treadle mechanism applied thereto, Fig. 2 is a vertical section through the same; and-Fig. 3 is a vertical section on the line a: m of Fig. 2.

In applying to sewing-machine tables already constructed or in use that class of treadle mechanism in which a crank is dispensed with, it has heretofore been necessary either to discard the old balance-wheel and make an entire new one with an elongated hub, or else to lengthen the hub of the old wheel by boring it out at the center and driving in one end of a hollow sleeve. The new balance-wheel thus required, or the alteration of the old one, materially increased the cost of the attachment and caused delay and inconvenience. My invention has for its object to overcome these difficulties and to enable me to utilize the old balance-wheel without alteration, in applying a treadle mechanism having no crank to an ordinary sewing-machine table already made or in use, and my invention consists in a mechanism actuated by a treadle or treadles and running upon the same stud as the balancewheel, said mechanism being connected with the balance-wheel by a suitable clutch or coupling, by which construction the cost of applying the treadle mechanism is greatly reduced, and the delay and inconvenience of sending the wheelto a machine-shop for alteration is avoided. d v

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it out.

In the said drawing, A represents the balance-wheel, which turns loosely upon a long stud, a, upon which is also placed a hollow sleeve, b, upon which turn two pulleys, B G, to each of which are secured the ends of two straps, c d, running down from opposite sides of the pulley and attached one to the treadle D and the other to the treadle E. The pulleys are held in place by a head, 9, on the outer end of the sleeve b; and to the inner end of this sleeve is secured, by means of a set-screw, 5, a bifurcated clutch, G, which embraces the stud or projection f on the balance-wheel A, so that they will revolve together. This projection f is found upon allof the ordinary sewing-machine balancewheels, which revolve upon a short pin or stud, one end of the pitman being attached to the treadle and the other end to the projection f. Within a groove in the outer end of each of the pulleys B (l is placed a curved pawl, 9, one of these pawls being pivoted to the head 0 and the other to the clutch G, and each pawl being drawn toward the center'by a light spring, h. The width of the outer portion 7 of each pawl is greater than the distance between the hub of the pulley and its rim, and consequently as each pulley is partially revolved or oscillated back and forth by the straps connected with the treadles the outer portion of its pawl is wedged between the hub and rim; and the motion of the pulley is thus communicated through the hollow sleeve 12 and clutch G to the balancewheel A, while when the pulley is rotated in the opposite direction the friction of the pawl is relieved so as to allow the wheel to receive an additional impetus in the same direction from the other pulley, the two pulleys being partially rotated, first in one direction and then in the other, alternately, by the two treadles D E. These pawls, however, form no part of my present invention, and any other suitable mechanism may be employed instead. Instead of the clutch G any other suitable clutch or coupling device may be used for connecting the mechanism operated by the treadles with the balance-wheel.

From the foregoing it will be seen that an improved treadle mechanism without a crank can thus be readily applied to a machine provided with an ordinary crank-treadle without requiring a new balance-wheel or any alteration whatever of the old one, which is a great convenience, as it avoids the necessity of sending the wheel to a machine-shop and materially lessens the cost of the attachment. It

'to; but 7 What I do claim as my invention, and desire to secure by Letters Patent, is

A mechanism actuated by a treadle or treadles and running upon the same stud as the balance-wheel, when said mechanism is connected with the balance-wheel by a clutch or coupling, substantially'as described.

Witness my hand this 3d day of June, A. D.

' AI B. SHAW. In presence of- P. E. TESOHEMACHER, W. J. CAMBRIDGE. 

